Patent GB-481370-A (GB)
Title: Apparatus for electrically ascertaining an elapse of time adapted for indicating the time taken for relays to operate or release
IPC: H03K17/28
Filed: 1936-09-11
Abstract: 481,370. Electromagnetic relays. SIEMENS BROS. & CO., Ltd., and RIBER, E. H. Sept. 11, 1936, No. 24767. [Class 38 (v)] [Also in Group XXXVI] In apparatus for electrically measuring the time which elapses between the beginning and the end of. an operation, e.g. the operating or release time of an electric relay, a. circuit charge at the beginning of the operation initiates the charging of a condenser CC through a resistance, and another circuit charge at the end of the operation stops further charging and connects the condenser to a potentiometer device RH, the setting of the latter, when the tapped potential balances the voltage of the condenser, as indicated by an instrument IG, serving as a measure of the elapse of time. In the arrangement shown, for measuring the operating and release lags of electromagnetic relays, the relay winding is connected between terminals 1, 3 and the relay contacts between terminals 4, 5. The charging resistance of the condenser includes a portion RC permanently in circuit, and portions RD, RE and RF, one or more of which can be short-circuited by operating a key KD to give three different ranges of lags. The terminals 6, 7 of the apparatus are connected to a battery or other D.C. source, and keys KA, KB are provided for varying the circuit connections to render it suitable for the conditions of different tests, the key KB being thrown to its operated position in cases where a contact is made at the conclusion of the operation of the relay, and left in its unoperated position when the relay operates to break a circuit. If it is desired to determine the operating lag of a circuit-closing relay, the key KA is placed in its central position and the key KB is operated ; on closing a starting key KC, operating circuits are closed for the relay under test and for a high-speed relay A, which responds and removes a short-circuit across the condenser circuit. The charging of the condenser then continues until the contacts of the relay under test close and complete the circuit of a highspeed relay B which, in response, disconnects the condenser from the charging circuit and connects it to the potentiometer RH through the indicating instrument IG. If the instrument indicates a want of balance, the potentiometer arm is adjusted and the operation is repeated, until the voltage of the condenser is equal to the tapped voltage on the potentiometer ; the latter is then a measure of the operating lag of the relay under test. The relays A, B are of the kind described in Specification 405,436 and have negligible operating lags. If it is desired to determine the releasing lag of a relay, the attainment of the released state being signified by the make or break of a contact, the key KA is thrown to its lower position and key KB is operated or not, according to whether a contact is made or broken. In cases where the release of the relay is effected by short-circuiting, the winding is connected between the terminals 2, 3 and the key KA is thrown to its upper position.